Length overall

Length overall, often abbreviated as (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking of the ship. It is the most commonly used way of expressing the size of a boat, and is also used for calculating the cost of a marina berth (for example, £2.50 per metre LOA).

LOA is usually measured on the hull alone. For sailing ships, this may exclude the bowsprit and other fittings added to the hull. This is how some racing boats and tall ships use the term LOA. However, other sources may include bowsprits in LOA. Confusingly, LOA has different meanings. "Sparred length", "Total length including bowsprit", "Mooring length" and "LOA including bowsprit" are other expressions that might indicate the full length of a sailing ship.

Often used to distinguish between the length of a vessel including projections (e.g. bow sprits, etc.) from the length of the hull itself, the Length on Deck or LOD is often reported. This is especially useful for smaller sailing vessels, as their LOA can be significantly different from their LOD.

Domestic worker

A domestic helper is a person who works within the employer's household. Domestic helpers perform a variety of household services for an individual or a family, from providing care for children and elderly dependents to housekeeping, including cleaning and household maintenance. Other responsibilities may include cooking, laundry and ironing, shopping for food and undertaking other household errands. Such work has always needed to be done but before the Industrial Revolution and the advent of labour saving devices, it was physically much harder.

Some domestic helpers live within their employer's household. In some cases, the contribution and skill of servants whose work encompassed complex management tasks in large households have been highly valued. However, for the most part, domestic work, while necessary, is demanding and undervalued. Although legislation protecting domestic workers is in place in many countries, it is often not extensively enforced. In many jurisdictions, domestic work is poorly regulated and domestic workers are subject to serious abuses, including slavery.

Coast guard

A coast guard or coastguard is a maritime security organization of a particular country. The term implies widely different responsibilities in different countries, from being a heavily armed military force with customs and security duties to being a volunteer organization tasked with search and rescue functions and lacking any law enforcement powers. However, a typical coast guard's functions are distinct from typical functions of both the navy (a pure military force) and a transportation police (a civilian law enforcement agency).

History

The modern Her Majesty's Coastguard of the United Kingdom was established in 1809 as the Waterguard, and was originally devoted to the prevention of smuggling as a department of the HM Customs and Excise authority. It was, however, also responsible for giving assistance to shipwrecks.

Each Water Guard station was issued with Manby's Mortar which was invented by Captain George William Manby in 1808. The mortar fired a shot with a line attached from the shore to the wrecked ship and was used for many years up and down the coastline. This began the process in which the Coastguard assumed a life saving role. In 1821 a committee of inquiry recommended that responsibility for the Preventative Water Guard be transferred to the Board of Customs. The Treasury agreed and in a Minute dated 15 January 1822, directed that the preventative services, which consisted of the Preventative Water Guard, cruisers, and Riding Officers should be placed under the authority of the Board of Customs and in future should be named the Coast Guard. In 1845 the Coastguard was subordinated to the Admiralty.

Length

In geometric measurements, length is the most extended dimension of an object. In the International System of Quantities, length is any quantity with dimension distance. In other contexts "length" is the measured dimension of an object. For example, it is possible to cut a length of a wire which is shorter than wire thickness.

Length may be distinguished from height, which is vertical extent, and width or breadth, which are the distance from side to side, measuring across the object at right angles to the length. Length is a measure of one dimension, whereas area is a measure of two dimensions (length squared) and volume is a measure of three dimensions (length cubed). In most systems of measurement, the unit of length is a base unit, from which other units are defined.

History

Measurement has been important ever since humans settled from nomadic lifestyles and started using building materials, occupying land and trading with neighbours. As society has become more technologically oriented, much higher accuracies of measurement are required in an increasingly diverse set of fields, from micro-electronics to interplanetary ranging.

Overall length

The overall length of an ammunition cartridge is a measurement from the base of the brass shell casing to the tip of the bullet, seated into the brass casing.

Handloaded cartridges and commercially available cartridges for firearms are normally created with a maximum length standardized by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI). A cartridge's overall length may be shorter than the maximum standard, equal to the standard, or sometimes even longer.

The maximum overall length is dictated by the need to fit into a box magazine of standard manufacture. For example, the .223 Remington cartridge, when loaded for use in the AR-15 rifle (or the military's M16 rifle), has to fit into the removable box magazine for that rifle. This dictates that the cartridge's maximum overall length be no greater than 2.260". However, for competition purposes during off-hand and slow fire prone match stages, the .223 Remington is loaded one cartridge at a time into the rifle's receiver. This allows for the cartridge to be longer than the standardized 2.260" SAAMI maximum overall length. These cartridges can be safely loaded to a length that has the ogive portion of the bullet just touching the rifle's lands. Many competitive shooters will make these cartridges 0.005" less than the truly maximum allowable overall length, for the sake of safety.